Fix mathematical terms

The term 'smallest numbers' was replaced by 'lowest numbers' in comments.
Fix prime factors not being ordered
Refactor primes to factorization

Refactored prime module to factorization module and added a function
which calculates the least common multiple of specified numbers to
this renamed module.
Fix bugs due to import issues

Fixed not importing the math module while using pow function out of it.
Fixed calling module primes which doesn't exist anymore.
Solve problem 5
Add possibility to solve all problems